#include <iostream>
#include <cstring>
#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;

void open(){
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
}

#define MAXN 100010
#define pb push_back
#define sz size()
int n,m,a,b,ans;
vector<int>g[MAXN];
bool used[MAXN];

void dfs(int a){
    used[a]=1;
    for (vector<int>::iterator it=g[a].begin();it!=g[a].end();it++){
        if (used[*it]) continue;
        dfs(*it);
    }
}

int main(){
    open();
    scanf("%d%d",&n,&m);
    for (int i=0;i<m;i++){
        scanf("%d%d",&a,&b);
        g[a].pb(b);
        g[b].pb(a);
    }
    ans=0;
    for (int i=1;i<=n;i++){
        if (used[i]) continue;
        ans++;
        dfs(i);
    }
    printf("%d\n",ans);
    return 0;
}